93xj getting hot

[93yj]

I hope somebody can answer my questions. A little back ground as to what I have done to this point. I took a 93 Cherokee I6 automatic that didn’t have a motor or transmission and dropped a 96’s drive train into it to use as my daily. I did swap out the 96’s oil pressure sending unit and the temp gage sending unit and put the 93’s sensors. The 93’s jeep didn’t have a dash cluster so I got one (without) the idiot lights, but the real gages and put that in. The 96’s motor had a new water pump, and radiator just installed into it before it was wrecked so I am pretty sure they are not the problems. I can touch all the hoses and they all get hot for the heating and cooling system(s) so it appears like the coolant is circulating. I can turn on the heat and it gets plenty toasty in the cab of the jeep. I have made sure to top off the antifreeze using 50/50 so I know I have plenty of that in the resiovor full mark. I did replace the thermastat thinking that it was maybe stuck closed. No luck with that.

Here in lays my problem. I start the jeep up and the temp gage starts to slowly creep up to the redline and then settle back down to 225 to 230ish. Every once in a while I will hear the electric fan kick on and the temp will drop back down to 215ish but will then creep back up to 225. I am wondering when I replaced the temp gage sensor I wasn’t able to get all the threads down flush with the block. The old part was removed with a 13mm deep socket, and the new part is 14mm. However, the valve cover is so close to the positioning of the part and the fire wall, that I am unable to get a 14mm deep socket over the temp sender to tighten it down fully. I have hand tightened it best I could, but did not want to overdo it for fear of break the plastic top off the brass bottom, and am unable to get an open ended wrench in there to crank it down any further. Coolant does not appear to be leaking, the gage is working due to the temps getting up to the 225ish. Is there an air pocket that could be trapped in the small space, and it just isn’t getting down to the coolant level? Is that even my problem? Thoughts ideas? Help me LOL!!!!

 

[bamacpl]

Whew! That's alot to read!!

Il admit i didnt read it all but did u try & clean the radiator core with that A/C foam cleaner stuff.... U can get it @ lowes for a cpl bucks. It's in an aerosol can.

 

[93yj]

Whew! That's alot to read!!

Il admit i didnt read it all but did u try & clean the radiator core with that A/C foam cleaner stuff.... U can get it @ lowes for a cpl bucks. It's in an aerosol can.

Hahah sorry it was a bit to read. Nope it is a brand new radiator though.

 

[DOSS]

having an XJ before I would say that your cooling system is working, your electric fan is working but i will bet your mechanical fan is slipping and not moving as much air as it should.

Try this, Bypass the power for the electric fan and just have the electric fan run constantly while the engine is running.. if you don't overheat you know that you don't have enough airflow and that it is the mechanical fan.. I would suggest doing a Ford Taurus electric fan upgrade (google should find out a walkthrough on how to do it)

 

[bamacpl]

Hahah sorry it was a bit to read. Nope it is a brand new radiator though.

Sorry, I admitted I didn't read it all ....
Good luck with it

 

[N-Smooth]

it could be your fan clutch like i was saying yesterday. there are a couple different ways to test it-

there is a little spring on it that you can turn 90 degrees counterclockwise and reattach it and that will make the clutch bypass temperature activation. if it still gets too hot your problem is somewhere else. i've never tried this one (haven't had to) but it's in manuals and stuff.

there is also the generic test: get the jeep to operating temperature and then shut it off, then try to spin the fan by hand- if it spins a whole revolution with ease that means you need a new fan clutch or to run a couple bolts through this one... it's up to you.

 

[93yj]

K I tried to spin the mechanical fan at running temp and its stiff....It will move but only slightly. I bipassed the electrical and it cooled it off from a runnimng temp of 225 235 to now down to 215 mostly 220 . It will hold that constant as long as the electric fan is on.... I am going to by pass the relay because it isnt turning on when he jeep gets hot. any other ideas?

 

[93yj]

Just to be on the safe side I dropped a new fan clutch in... same thing. Still gets up to 220ish

 

[irish1371]

is the set up you ave a 1 or 2 spd fan? I read electric fan in your post. The fan maybe only wired/relayed for 1 speed when it needs the 2nd to kick in to cool correctly? Also how is your fan shroud? seen alot of them made to fit and they leave gaps. This lets air bypass the radiator and let em run hot.

Just a few ideas to kick around

 

[DOSS]

you might want to get an IR temp test done and see if that is the actual temp you are reaching or if it is just your gauge too, as you have not actually gone all steam and stuck on the side of the road it could just be that the gauge reads high? Also you said you have a new radiator but did you clean and flush the engine block, could you have a slow area somewhere? Water pump getting weak? Ahh the reasons that I USED to own a jeep

 

[93yj]

is the set up you ave a 1 or 2 spd fan? I read electric fan in your post. The fan maybe only wired/relayed for 1 speed when it needs the 2nd to kick in to cool correctly? Also how is your fan shroud? seen alot of them made to fit and they leave gaps. This lets air bypass the radiator and let em run hot.

Just a few ideas to kick around

I am not sure if it is a 1 or 2 speed fan. How would I check to see if it has the 2 speed? Yes it has the entire fan shroud

 

[N-Smooth]

it's a stock xj e-fan so it's just 1 speed

 

[93yj]

you might want to get an IR temp test done and see if that is the actual temp you are reaching or if it is just your gauge too, as you have not actually gone all steam and stuck on the side of the road it could just be that the gauge reads high? Also you said you have a new radiator but did you clean and flush the engine block, could you have a slow area somewhere? Water pump getting weak? Ahh the reasons that I USED to own a jeep

What kind of shops could I take it two to get a temp test done? No it actually hasn't steamed and boiled over. I just keep reading on all the xj web sites that the motor shouldn’t be running much warmer than the 210 or I am going to start warping the head of the motor. The radiator is brand new. I should pony up and have the system power flushed at this point. you say that you used to own a jeep? LOL

 

[93yj]

it's a stock xj e-fan so it's just 1 speed

hahah thanks Nate

 

[N-Smooth]

most shops should have an IR tester, i know Jeff has one at his place

 

[ricsrx]

my 89 I6 was also overheating, alot like your problem, I had a good mechanical fan and jumpered the electrical fan to run all the time but that was just a bandaid.
the problem was the overflow tank, or more specific the cap, if the systems are the same replacing the bottle and cap fixed my problem. i was not building any pressure to get the system to work and because the cap is on the tank you cant notice the problem.

i lived with my problem for years before finaly getting fixed right, the bottle and caps are inexspensive to replace.

 

[N-Smooth]

sounds like you had a closed cooling system, his is open since it's a 93/96 mutt.

i'm confused about what else it could be since you have confirmed that everything is flowing by checking that all hoses have pressure and heat. it has to be the radiator or poor flow from a crappy water pump or a clog somewhere in the system.

mine used to get up to 220-230 when it was like 50 degrees outside. i put in a new radiator and now it doesn't get hot even when i'm on the trail in 90 degree heat all day.

does the radiator look okay physically? not a bunch of smashed fins or anything, right? what about the condenser or a tranny cooler or anything else that might be in front of it?